1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121

//! The abstract **Camera** base class holds generic camera options
//! and defines the interface that all camera implementations must
//! provide.

// std
use std::sync::Arc;
// pbrt
use crate::cameras::environment::EnvironmentCamera;
use crate::cameras::orthographic::OrthographicCamera;
use crate::cameras::perspective::PerspectiveCamera;
use crate::cameras::realistic::RealisticCamera;
use crate::core::film::Film;
use crate::core::geometry::{Point2f, Ray, Vector3f};
use crate::core::interaction::InteractionCommon;
use crate::core::light::VisibilityTester;
use crate::core::pbrt::{Float, Spectrum};

// see camera.h

pub enum Camera {
    Environment(Box<EnvironmentCamera>),
    Orthographic(Box<OrthographicCamera>),
    Perspective(Box<PerspectiveCamera>),
    Realistic(Box<RealisticCamera>),
}

impl Camera {
    pub fn generate_ray_differential(&self, sample: &CameraSample, ray: &mut Ray) -> Float {
        match self {
            Camera::Environment(camera) => camera.generate_ray_differential(sample, ray),
            Camera::Orthographic(camera) => camera.generate_ray_differential(sample, ray),
            Camera::Perspective(camera) => camera.generate_ray_differential(sample, ray),
            Camera::Realistic(camera) => camera.generate_ray_differential(sample, ray),
        }
    }
    pub fn we(&self, ray: &Ray, p_raster2: Option<&mut Point2f>) -> Spectrum {
        match self {
            Camera::Environment(camera) => camera.we(ray, p_raster2),
            Camera::Orthographic(camera) => camera.we(ray, p_raster2),
            Camera::Perspective(camera) => camera.we(ray, p_raster2),
            Camera::Realistic(camera) => camera.we(ray, p_raster2),
        }
    }
    pub fn pdf_we(&self, ray: &Ray) -> (Float, Float) {
        match self {
            Camera::Environment(camera) => camera.pdf_we(ray),
            Camera::Orthographic(camera) => camera.pdf_we(ray),
            Camera::Perspective(camera) => camera.pdf_we(ray),
            Camera::Realistic(camera) => camera.pdf_we(ray),
        }
    }
    pub fn sample_wi<'a, 'b>(
        &self,
        iref: &'a InteractionCommon,
        lens_intr: &'b mut InteractionCommon,
        u: Point2f,
        wi: &mut Vector3f,
        pdf: &mut Float,
        p_raster: &mut Point2f,
        vis: &mut VisibilityTester<'a, 'b>,
    ) -> Spectrum {
        match self {
            Camera::Environment(camera) => {
                camera.sample_wi(iref, lens_intr, u, wi, pdf, p_raster, vis)
            }
            Camera::Orthographic(camera) => {
                camera.sample_wi(iref, lens_intr, u, wi, pdf, p_raster, vis)
            }
            Camera::Perspective(camera) => {
                camera.sample_wi(iref, lens_intr, u, wi, pdf, p_raster, vis)
            }
            Camera::Realistic(camera) => {
                camera.sample_wi(iref, lens_intr, u, wi, pdf, p_raster, vis)
            }
        }
    }
    pub fn get_shutter_open(&self) -> Float {
        match self {
            Camera::Environment(camera) => camera.get_shutter_open(),
            Camera::Orthographic(camera) => camera.get_shutter_open(),
            Camera::Perspective(camera) => camera.get_shutter_open(),
            Camera::Realistic(camera) => camera.get_shutter_open(),
        }
    }
    pub fn get_shutter_close(&self) -> Float {
        match self {
            Camera::Environment(camera) => camera.get_shutter_close(),
            Camera::Orthographic(camera) => camera.get_shutter_close(),
            Camera::Perspective(camera) => camera.get_shutter_close(),
            Camera::Realistic(camera) => camera.get_shutter_close(),
        }
    }
    pub fn get_film(&self) -> Arc<Film> {
        match self {
            Camera::Environment(camera) => camera.get_film(),
            Camera::Orthographic(camera) => camera.get_film(),
            Camera::Perspective(camera) => camera.get_film(),
            Camera::Realistic(camera) => camera.get_film(),
        }
    }
    // extra
    pub fn get_clipping_start(&self) -> Float {
        match self {
            Camera::Perspective(camera) => camera.get_clipping_start(),
            _ => 0.0 as Float,
        }
    }
    pub fn adjust_to_clipping_start(&self, sample: &CameraSample, ray: &mut Ray) {
        match self {
            Camera::Perspective(camera) => camera.adjust_to_clipping_start(sample, ray),
            _ => {}
        }
    }
}

#[derive(Debug, Default, Copy, Clone)]
pub struct CameraSample {
    pub p_film: Point2f,
    pub p_lens: Point2f,
    pub time: Float,
}